mpl-switch is a simple installer and version switcher for MPL.

It creates and maintains a ~/.mpl directory containing local installs of MPL, organized by commit ID. Note that it is "safe" at any moment to delete this ~/.mpl directory; everything in here can be regenerated automatically.

Just clone this repo and add the repo directory to your PATH.

$ git clone https://github.com/MPLLang/mpl-switch.git
$ export PATH="$(pwd -P)/mpl-switch:$PATH"

Run the following only once (make sure you put the export PATH command in your .profile or .bashrc or whatever you use):

$ mpl-switch init
$ export PATH="~/.mpl/bin:$PATH"

To install a particular version of MPL (this will take a while):

$ mpl-switch install <COMMIT|TAG>

To select a version of MPL to use:

$ mpl-switch select <COMMIT|TAG>

To see installed versions and which is currently selected:

$ mpl-switch list

Here's an example on my machine.

$ mpl-switch init
initialized /usr0/home/swestric/.mpl
make sure this is in your PATH: /usr0/home/swestric/.mpl/bin

$ export PATH="~/.mpl/bin:$PATH"
$ which mpl
/usr0/home/swestric/.mpl/bin/mpl

$ mpl-switch install v0.5
...
$ mpl-switch install v0.5.1
...

$ mpl-switch select v0.5.1

$ mpl-switch list
INSTALLED VERSIONS:
    v0.5
  * v0.5.1

$ mpl-switch current
v0.5.1

$ mpl
MLton [mpl] 20241218.162358-g39c953777